Enable GuC / HuC firmware loading

Warning: Using GVT-g graphics virtualization by setting enable_gvt=1 is not supported as of linux 4.18.8 when GuC/HuC is also enabled. The i915 module would fail to initialize as shown in system journal.

For Skylake and newer processors, some video features (e.g. CBR rate control on SKL low-power encoding mode) may require the use of an updated GPU firmware, which is currently (as of 4.16) not enabled by default. Enabling GuC/HuC firmware loading can cause issues on some systems; disable it if you experience freezing (for example, after resuming from hibernation).

For those processors it is necessary to add i915.enable_guc=2 to the kernel parameters to enable both GuC and HuC firmware loading. Alternatively, if the initramfs already includes the i915 module (see Kernel mode setting#Early KMS start), you can set these options through a file in /etc/modprobe.d/, e.g.:

/etc/modprobe.d/i915.conf

options i915 enable_guc=2

It is possible to enable both GuC/HuC firmware loading and GuC submission by using the enable_guc=3 module parameter, although this is generally discouraged and may even negatively affect your system stability.

Additional options are added by the user on new lines below Driver.
For the full list of options, see the intel(4) man page.

Note:

You may need to indicate Option "AccelMethod" when creating a configuration file, even just to set it to the default method (currently "sna"); otherwise, X may crash.

You might need to add more device sections than the one listed above. This will be indicated where necessary.

Module-based options

The i915 kernel module allows for configuration via module options. Some of the module options impact power saving.

A list of all options along with short descriptions and default values can be generated with the following command:

$ modinfo -p i915

To check which options are currently enabled, run

# systool -m i915 -av

You will note that many options default to -1, resulting in per-chip powersaving defaults. It is however possible to configure more aggressive powersaving by using module options.

Warning: Diverting from the defaults will mark the kernel as tainted from Linux 3.18 onwards. This basically implies using other options than the per-chip defaults is considered experimental and not supported by the developers.

Framebuffer compression (enable_fbc)

Making use of Framebuffer compression (FBC) can reduce power consumption while reducing memory bandwidth needed for screen refreshes.

To enable FBC, use i915.enable_fbc=1 as kernel parameter or set in /etc/modprobe.d/i915.conf:

/etc/modprobe.d/i915.conf

options i915 enable_fbc=1

Note: Framebuffer compression may be unreliable or unavailable on Intel GPU generations before Sandy Bridge (generation 6). This results in messages logged to the system journal similar to this one:

[ 2360.475430] [drm] not enough stolen space for compressed buffer (need 4325376 bytes), disabling
[ 2360.475437] [drm] hint: you may be able to increase stolen memory size in the BIOS to avoid this

The solution is to disable frame buffer compression which will imperceptibly increase power consumption (around 0.06 W). In order to disable it add i915.enable_fbc=0 to the kernel line parameters. More information on the results of disabled compression can be found here.

Fastboot

The goal of Intel Fastboot is to preserve the frame-buffer as setup by the BIOS or bootloader to avoid any flickering until Xorg has started [3].

To enable fastboot, set i915.fastboot=1 as kernel parameter or set in /etc/modprobe.d/i915.conf:

/etc/modprobe.d/i915.conf

options i915 fastboot=1

Warning: This parameter is not enabled by default and may cause issues on some systems [4].

Intel GVT-g Graphics Virtualization Support

Tips and tricks

Setting scaling mode

center: resolution will be kept exactly as defined, no scaling will be made,

full: scale the resolution so it uses the entire screen or

full_aspect: scale the resolution to the maximum possible but keep the aspect ratio.

If it does not work, try:

$ xrandr --output LVDS1 --set "scaling mode" param

where param is one of "Full", "Center" or "Full aspect".

Note: This option currently does not work for external displays (e.g. VGA, DVI, HDMI, DP). [5]

Hardware accelerated H.264 decoding on GMA 4500

The libva-intel-driver package only provides hardware accelerated MPEG-2 decoding for GMA 4500 series GPUs. The H.264 decoding support is maintained in a separated g45-h264 branch, which can be used by installing libva-intel-driver-g45-h264AUR package. Note however that this support is experimental and its development has been abandoned. Using the VA-API with this driver on a GMA 4500 series GPU will offload the CPU but may not result in as smooth a playback as non-accelerated playback. Tests using mplayer showed that using vaapi to play back an H.264 encoded 1080p video halved the CPU load (compared to the XV overlay) but resulted in very choppy playback, while 720p worked reasonably well [6]. This is echoed by other experiences [7].
Setting the preallocated video ram size higher in bios results in much better hardware decoded playback. Even 1080p h264 works well if this is done.
Smooth playback (1080p/720p) works also with mpv-gitAUR in combination with ffmpeg-gitAUR and libva-intel-driver-g45-h264AUR. With MPV and the Firefox plugin "Watch with MPV"[8] it is possible to watch hardware accelerated YouTube videos.

This option is problematic for applications that are very picky about vsync timing, like Super Meat Boy.

This option does not work with UXA acceleration method, only with SNA.

Disable Vertical Synchronization (VSYNC)

Useful when:

Chomium/Chrome has lags and slow performance due to GPU and runs smoothly with --disable-gpu switch

glxgears test does not show desired performance

The intel-driver uses Triple Buffering for vertical synchronization, this allows for full performance and avoids tearing. To turn vertical synchronization off (e.g. for benchmarking) use this .drirc in your home directory:

Warning: Do not use driconf to create this file. It is buggy and will set the wrong driver.

SNA issues

SNA is the default acceleration method in xf86-video-intel. If you experience issues with SNA (e.g. pixelated graphics, corrupt text, etc.), try using UXA instead, which can be done by adding the following line to your configuration file:

X freeze/crash with intel driver

Some issues with X crashing, GPU hanging, or problems with X freezing, can be fixed by disabling the GPU usage with the NoAccel option - add the following lines to your configuration file:

Option "NoAccel" "True"

Alternatively, try to disable the 3D acceleration only with the DRI option:

Option "DRI" "False"

Baytrail complete freeze

If you are using kernel > 3.16 on Baytrail architecture and randomly encounter total system freezes, the following kernel option is a workaround until this bug is fixed in the linux kernel.

intel_idle.max_cstate=1

This is originally an Intel CPU bug that can be triggered by certain c-state transitions. It can also happen with Linux kernel 3.16 or Windows, though apparently much more rarely.
The kernel option will prevent the freeze by avoiding c-state transitions but will also increase power consumption.

Adding undetected resolutions

Weathered colors (color range problem)

This section is being considered for removal.

Reason: This bug has been resolved, closed and is patched in Kernel 4.18.8. (Discuss in Talk:Intel graphics#)

Kernel 3.9 contains a new default "Automatic" mode for the "Broadcast RGB" property in the Intel driver. It is almost equivalent to "Limited 16:235" (instead of the old default "Full") whenever an HDMI/DP output is in a CEA mode. If a monitor does not support signal in limited color range, it will cause weathered colors.

Note: Some monitors/TVs support both color range. In that case an option often known as Black Level may need to be adjusted to make them handle the signal correctly. Some TVs can handle signal in limited range only. Setting Broadcast RGB to "Full" will cause color clipping. You may need to set it to "Limited 16:235" manually to avoid the clipping.

This can be fixed by disabling execlist support which was changed to default on with kernel 4.0. Add the following kernel parameter:

i915.enable_execlists=0

This is known to be broken to at least kernel 4.0.5.

Lag in Windows guests

The video output of a Windows guest in VirtualBox sometimes hangs until the host forces a screen update (e.g. by moving the mouse cursor). Removing the enable_fbc=1 option fixes this issue.

Screen flickering

Panel Self Refresh (PSR), a power saving feature used by Intel iGPUs is known to cause flickering in some instances FS#49628FS#49371FS#50605. A temporary solution is to disable this feature using the kernel parameteri915.enable_psr=0.

OpenGL 2.1 with i915 driver

The update of mesa from version 13.x to 17 may break support for OpenGL 2.1 on third gen Intel GPUs (GMA3100, see here), as described in this article, reverting it back to OpenGL 1.4. However this could be restored manually by setting /etc/drirc or ~/.drirc options like:

Note: the reason of this step back was Chromium and other apps bad experience. If needed, you might edit the drirc file in a "app-specific" style, see here, to disable gl2.1 on executable chromium for instance.

KMS Issue: console is limited to small area

One of the low-resolution video ports may be enabled on boot which is causing the terminal to utilize a small area of the screen. To fix, explicitly disable the port with an i915 module setting with video=SVIDEO-1:d in the kernel command line parameter in the bootloader. See Kernel parameters for more info.

If that does not work, try disabling TV1 or VGA1 instead of SVIDEO-1. Video port names can be listed with xrandr.